(1) Field of the Invention
The present invention relates to a display device and an image display system for displaying images on a display device, such as a display device using a liquid crystal display device or a display device using a CRT, according to output signals from a graphic controller mounted to a computer.
(2) Description of the Related Art
On a display device connected to a computer, application softwares which are executed by the computer according to user's processing objects are displayed. Generally, a plurality of windows are displayed on the display device, and images of the application softwares are displayed in the respective windows.
As the above-mentioned application softwares, for example, there are a word processor for mainly processing texts, a retouch software for mainly processing photographic images and the like. The image quality of texts, which is desirable for a user to perform operations comfortably, is greatly different from that of photographic images. Therefore, in a conventional display device, the user adjusts the image quality suitably according to an application software being used.
However, there is the following problem in such conventional display device.
Namely, since a plurality of windows are displayed on the display device and application softwares are displayed in the respective windows, once the user adjusts the image quality of the display device suitably for a word processor, for example, the image quality remains the same even when the user selects a retouch software window behind the word processor window. The user has to use the retouch software with the image quality which is not suitable for the retouch software, or has to readjust the image quality so as to be suitable for the retouch software. Thus, it is troublesome to manually adjust the image quality every time a different software is selected.
In order to reduce the above troublesome operation, there exists a method in which various image qualities are preset in a display device, and whenever a user changes over application softwares, the user manually selects one image quality suitable for the software being currently selected among the preset image qualities, using an image quality selection button provided to the display device. However, even if such method is used, adjustment and changeover of image quality is still troublesome for the user.